Field of the Invention
The present invention relates to a multi-layer shrink film comprising at least one shrink base layer and an inkjet printable layer, the latter comprising at least one cellulose-based binding agent, to methods of making such a multi-layer shrink film and of providing graphical information by means of such a multi-layer shrink film, to articles provided with such a multi-layer shrink film as well as to the use of a particular cellulose-based binding agent in the inkjet printable layer of an inkjet printable shrink film.
Inkjet printing is a widely used process for applying graphical information, including text and (optionally multi-color) images, to a substrate. In such a process, solvent-containing ink droplets are deposited from a nozzle onto an absorbent substrate, e.g. paper, to form the image. Rapid absorption of the ink into the substrate is a requirement for good image quality and to obtain images with a high color gamut and without printing defects. Most substrates need a special inkjet ink absorbing coating for good printing results. The inkjet coating formulations have to be adjusted to the specific substrate, papers for instance need different coatings than films. Moreover, there are numerous articles which cannot be imaged in good quality by direct inkjet printing, including, for instance, articles made of glass, metals, plastics and the like.
In addition, in general it is difficult to provide articles having uneven and/or curved surfaces with graphical information in any direct printing process.
Description of the Related Art
For this reason, printable shrink films have been developed which offer great freedom in packaging design regarding color and shape. These films comprise a mono- or biaxially oriented (stretched) polymer plastic film which reverts from its oriented to its relaxed state when heat is applied, thus shrinking and conforming tightly to the surface of the articles it is covering. Shrink films are nowadays widely used for decorating, labelling, packaging and/or wrapping all different kinds of articles, for instance including, but not being limited to, bottles, cans, containers, cartons, boxes, pallet loads, foods, cosmetics, cleaning agents, books, CDs, DVDs etc. In order to be inkjet printable, shrink films usually have to be provided with at least one ink receptive layer in addition to the conventional shrink layer, as described, for instance, in EP 0 899 121 A1, WO 01/05600 A1 or US 2013/0205629 A1. However, in such multi-layer shrink films the individual layers have to be carefully adapted to each other, in order to avoid brittleness, cracking, wrinkling or even delamination of the layers upon shrinking, but at the same time achieving a sufficient effectiveness of print drying.